There are a couple of ways information can be "hidden" in a picture.
The first is in the pictures properties. To find that, you right click on the picture, SAVE AS (use the name of the picture that is there) and save it to your desktop. Then, go to your desktop, right click on the picture, choose PROPERTIES and look at the Summary. You just might find a clue there.
The other place to find a hidden message is in the picture itself. Follow the steps above to save the picture. Open it up in a program like Microsoft Photo Editor, Photoshop, GIMP, etc. Something that allows you to adjust the brightness, contrast, gamma and color settings. It's best if you have a preview option, so you can see if you are adjusting things the right way.
Good luck!